Motion-picture-projecting machine.



J. c. CHAMBERS.

MOTION PICTURE PROJECTING MACHINE. APPLICATION FILED AUG.29. 1918.

1,300,247, Patented Apr. 15, 1919. I

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1. c. CHAMBERS.

MOTION PICTURE PROJECHNG MACHINE. APPLICATION FILED AUG.29, I918.

Patented Apr. 15, 1919.

2 SHEETS-SHEET 2. fIgfir/Zzmes Chambers- A T'TORNE Y.

' speed of advance slackened thing therefore happens to the tion is to matically cutting oil or intercepting the JAMES C. CHAMBERS, 01: ST. LOUIS MISSOURI.

MOTION-PIGTDBE-PROJ ECTIN G MACHINE.

To all whom it may concern:

Be it known that I, JAMES C. CHAMBERS, a citizen of the United States, residingat St. Louis, State of Missouri, have invented certain new and useful Improvements in Motion Picture Projecting Machines, of which the following is a full, clear, and exact description, reference being had to the accompanying, 4 hereof;

drawings, forming a part- Specification of Iietters Patent.

The present improvement is directed to motion picture projecting machines, these pictures as well understood in the art, be-

mg carried on films of highly inflammable material. To secure'the projection of the pictures a heat generated by the light-being sufiicient to ignite the film should the movement of the latter be arrested for any appr cia le length of time during the normal operation of the machine. The object of the present invenprovide suitable means for autolight rays in the event that the film becomes in any way disarranged or:ta1 igled, or'its or arrested, thereby saving the film from destruction. As well understood in the art, the film and unwinds from anwmds on one reel other, and is under tenslon while in service or in motion. In the presentembodiment of my invention this tension is availed. of to control not 0 lythe action of the light shield or cut-oil", but the action of the contacts or wipers which close the circuit of the electric current operating the motor by which the film is propelled. lVhen anyfihn which tends to remove the tension under which the same operates under normal service conditions, the light shield or cut-oil instantly asserts itself and the light rays are intercepted so that the film can not take fire. The advantages of the invention will be fully apparent from the following detailed descrip tion inconnection with the accompanying drawings in which Figure 1 represents a side elevation of a conventional motion picture projecting machine showing my invention applied thereto; Fig. 2 is an enlarged sideelevation of the bottom set of connections entering into construction of the light-shield controlling mechanism; Fig. 3 is an inside end elevae. tion of the sprocket and guide spools,"showing the shutter or cover plate for closing the powerful light is necessary, the

Patented Apr. 15, 1919.

A man filed August 2a, 1918. Serial No. 251,919.

. slottraversed by the oscillating spindle of the sprocket spool; Fig. 4 is a vertical crosssectional detail on the line H of Fig. 2; F 1g. 5 is a horizontal section on the zig-zag l ne 5.5 of Fig. 2': Fig. 6 side elevational detail of the drop-lever and the slneld or cut-off suspended therefrom; Fig, 7 is an end view of Fig. 6; Fig. 8 is a horizontal cross-sectional detail on the line 88 of' Fig. 6; F ig; 9 is a detached perspective of the wiper plate carried by the oscillating angle weighted tripping arm or lever issecured; and Fig. 10 is a vertical sectional detail on the line 10l0 of Fig. 5.

Referring to the drawings, L, represents a projecting lantern, H, the motion-head or film-advancing mechanism operated by the electric motor M, the filma'unwinding from a reel or spindle in the magazine A, and winding on a reel or spindle in the magazine A, motion being imparted to the film and to the reels by mechanism well known in the artand shown more or less conventionally in the drawings. The film in its passage from the unwinding to the winding reel is maintained taut, suificieut tension being imposed thereon to preserve uniform: ity of .speed and positiveness of travel and prevent clogging or congestion. The tension or tautness ot' the film is availed of under my invent-ion to bring about the proper control of the mechanism by which the light-shield or cut-off is actuated with any change or relaxation of said tension. My invention has for its object to cut off the light (and heat) rays while the motion head is in operation and under circumstances where the film may accidentally tear or its travel becomes arrested or is' continued from the unwinding reel without correspondingly wrapping on the winding reel; and in general in cases where the tension or taut-ness of the film is for any reason relaxerj. In the present embodiment .of my invent-i the magazine-A a plate or mounting 1, said plate being provided with a stationary spindle or screw-bolt 2 over whose inner threaded portion is loosely passed the guide spool 3 maintained in proper position on the bolt by the nut n. The outer-smooth or unthreaded is an enlarged -bracket to which the portion of therbolt 2 supports an oscillating angle-b racket 'ersed by the larged head bolt. The head it is provided with a screwthe slot etpermanently covered (so as to pro- 'tect the film on the inside from extraneous influences) I pass over the members 2 and G a shutter o cover plate 8, which is maintained in engagement with the inner face of the magazine wall by thespool 3. The axis of 'the' spindle 6 is substantially with the axis of the outwardly projecting arm of the angle bracket 4, that is to say, the arm disposed at right angles to the plate 1.

' To the free end of this arm is pivotally secured one end .of a vertically oscillating block or short link 9'through whose free end is passed a push rod or bar 10, which may be adjusted to any desired position and then firmly secured onset-screwed toJthe link by the screw 11'." The upper end of the rod 10- is pivotally secured in any desired manner to the short. arm of a vertically oscillating j lever-l2 fulcr-urned at'the upper term nal of a 7 'ost or staff 13 which is secured nany adjusted position to a bracket 14 leading from, the plate 1. The free end .of the long justable bracket or. bearing15 supporting 0 hung or suspended the'dro p-shield 17, said shield or cut-ofi' being mounted to come in,

. h .the path of the rays-1', 1', issuing from the hood B of thel'projecting lantern L, when dropped to its lowest position, thereby inter- '15 -'as above related.

apart by insulating material are the station- 'ary wipers or contacts 18, the lobe 19 of one of the wipers connecting directly to the wire to. To the under side of the link-supporting arm of the bracket 4 is secured a plate 20 (properly insulated) terminating atone end in a wiperor contact 21 adapted to playbe tween and along the inner faces of the spring contacts 18, the opposite end of the plate 20 beinglprovided with a lobe or loop 22 to which-t e wire wis' secured, it being understood that'the wires w, to, form the circuit wires forthe current fed to the motor M by which the film is advanced.

The operation of the device is apparent 'from the drawings, but may be briefly d8? M66 scribed as follows: When the machine is incoinci dent 'ing - or bolt 2. and

arm of the lever 12 is provided with an elongated slot 8 along which is secured an -ad-- cepting the rays before they can do any harm to the film a under circumstances such v or the oscillating end of the bracket 4 carryservice and the film maintained taut or under tension in its passage from the reel of one magazine to that of the other, the spool 7 bearing against the 'film under the action of the weighted arm 5 leading from the 70 oscillating bracket 4, sustains the arm in a raised position, the link-supporting leg of the bracket 4 being depressed, and the push rod 10 pulled down so as to holdthe long arm of the lever 12 elevated, and the dropshield 17 raised above the path of the rays r, r, the rays'being' thereby left free to. pass to the film through the usual window 25, as well understood in the art. .In the event lioweve that'anything happens. to the film 30 so as t .release the tension imposed thereon (for example a break in the film), the film being no longer under tension 'will release the spool 7 allowing the lever or arm 5'to drop, whereupon .the depressed end of the angle-bracket 4 to which the arm is coupled, is raised or oscillated upw'ard,-thereby lifting through the slot 8 the spindle 6 supportthe spool 7 (the plate- 8 oscillating with the spindle 6 about the axis ofthe spindle keeping the slot permanently covered), and pushing upward the rod 10, the'latter in turn forcing down the long arm of'the lever 12 and dropping the shield 17 4 across the path of the light rays. The rays are thus automatically cut off from the film;

and in the event the operator is not on hand ,to stop the motion head, the film is at least safe from any injury by fire-as the. heat from the rays can no longer reach the film.

- .At the same time that the shield 17 is.

dropped into position across the rays 1", 1", it will be observed that the raised end of the bracket 4 has withdrawn the wiper 21 from contact with the wipers 18,. so that the .motor circuit is broken causing the motor Mand motion head to come to a stop and thus arresting further advance of the film. As soon as t e film has been restored and the accident remedied the parts are reset.

Since the parts 4 and 5 operate as a unit,

they may for convenience vbe jointly con.- Secured to the plate 1 and maintained .mounted. ,It will be observed that in the operation of thedevice the free or oscillatmg end of the short arm of'the lever 12 describes an arc curvedvin the opposite .di-

rection from the are described by the free end of the short arm .of the tripping lever 12 ing the spindlet. Since the push rod 10 has its opposite ends coupled to the oscillating terminals of these respective members, it is apparent that without the provision of the oscillating link 9 the parts would bind and would not permit the rod to maintain a permanently vertical position. It is for this reason-that the link 9 is employed in the construction here shown. The

device may be changed in manypartlculars require no description in the present connection.

Having described my invention what I claim is:

1. In a motion picture projecting machine, a traveling film maintained under tension, 2. light source, means for conducting the rays to the film, a fixed support, a vertically oscillating weighted lever fulcrumed about a fixed spindle on said-support, a guide spool on said fulcrum spindle, a spindle secured to the free end ofthe' short arm of the weighted lever in proximity to the fulcrum spindle, a sprocket spool on the last named spindle,-an arm on the weighted lever positioned opposite the spindle, carrying the sprocket spool, a link block pivotally coupled to the free end of the arm aforesaid, a post, a vertically oscillating lever fulcrumed to said post and provided with a short and long arm, a' push rod pivotally connected to the short arm of said lever and connected to the link block aforesaid, a rod projecting laterally from the long arm of the lever, and a shield suspended from the rod'af oresaid, and adapted to be dropped across the light rays upon a release of the weighted lever by the film due to a removal or reduction in the normal tension imposed on the film, the parts operating substantially as, and for the purpose set forth. a

2. In combination with a magazine of a motion picture projecting machine, a weighted tripping lever mounted on the outer wall of the magazine, a fulcrum spindle for the lever projecting into the magazine, a guide spool or roller for the film mounted on the spindle, a second spindle leading from the short arm of the tripping lever through a slot in the wall of the magazine, a sprocket spool onsaid second spindle engaging the film, the latter being sufficiently taut to maintain the weighted arm of the tripping lever elevated, and the short arm'carrying the sprocket spool depressed, a source of light, a drop-shield, intermediate connections between the tripping lever and drop shield operating to force the shield across the path of the light rays coming from the light source upon a release of the tripping lever due to a removal or reduction of the normal tension imposed on the film, and a shutter or cover plate opposite the slot in the wall of the magazine, traversed by the fulcrum and oscillating spool-supporting spindles leading from the tripping lever, the shutter being free to oscillate with the spindle supporting the sprocket spool, about the axis of the fulcrum spindle.

3. In a motion picture projecting machine, a traveling film maintained under tension, a light source, means "'or conducting the rays to the film, a fixed support, a vertically oscillating weighted lever fulcrumed about a fixed spindle on said support, a spindle secured to the free end of the short arm of the weighted lever in proximity to the fulcrum spindle, a sprocket spool on the last named spindle, an arm on the weighted lever positioned opposite the spindle carrying the sprocket spool, a link block pivotally coupled to thefree end of the arm aforesaid, a post, a vertically oscillating lever fulcrumed to said post and provided with a short and long arm, a-push rod pivotally connected to the short arm of said lever and connected to the link block aforesaid, a rod projecting laterally fromthe long arm of the lever, and a shield suspended from the rod aforesaid, and

adapted to be dropped across the light rays upon a release of the weighted lever by the film due to a removal or reduction in the normal tension imposed on the film, the parts operating substantially as, and for the purpose set forth.

In testimony whereof I atfix my signature, in'presence of two witnesses.

JAMES C. CHAMBERS.

Witnessesr.

EMIL STAREK, ELSE M; SIEGEL. 

